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SubjectRe: [PATCH 1/2] cpuidle: Drop disabled field from struct cpuidle_state
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On 21/11/2019 19:41, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> After recent cpuidle updates the "disabled" field in struct
> cpuidle_state is only used by two drivers (intel_idle and shmobile
> cpuidle) for marking unusable idle states, but that may as well be
> achieved with the help of a state flag, so define an "unusable" idle
> state flag, CPUIDLE_FLAG_UNUSABLE, make the drivers in question use
> it instead of the "disabled" field and make the core set
> CPUIDLE_STATE_DISABLED_BY_DRIVER for the idle states with that flag
> set.
>
> After the above changes, the "disabled" field in struct cpuidle_state
> is not used any more, so drop it.
>
> No intentional functional impact.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>
> Changes from RFC:
>
> - Do not add extra braces (unrelated to the rest of the patch).
>
> ---
> arch/sh/kernel/cpu/shmobile/cpuidle.c | 8 ++++----
> drivers/cpuidle/cpuidle.c | 2 +-
> drivers/cpuidle/poll_state.c | 1 -
> drivers/idle/intel_idle.c | 6 +++---
> include/linux/cpuidle.h | 2 +-
> 5 files changed, 9 insertions(+), 10 deletions(-)
>
> Index: linux-pm/drivers/idle/intel_idle.c
> ===================================================================
> --- linux-pm.orig/drivers/idle/intel_idle.c
> +++ linux-pm/drivers/idle/intel_idle.c
> @@ -1291,8 +1291,8 @@ static void sklh_idle_state_table_update
> return;
> }
>
> - skl_cstates[5].disabled = 1; /* C8-SKL */
> - skl_cstates[6].disabled = 1; /* C9-SKL */
> + skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE; /* C8-SKL */
> + skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE; /* C9-SKL */
> }
> /*
> * intel_idle_state_table_update()
> @@ -1355,7 +1355,7 @@ static void __init intel_idle_cpuidle_dr
> continue;
>
> /* if state marked as disabled, skip it */
> - if (cpuidle_state_table[cstate].disabled != 0) {
> + if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
> pr_debug("state %s is disabled\n",
> cpuidle_state_table[cstate].name);
> continue;
> Index: linux-pm/include/linux/cpuidle.h
> ===================================================================
> --- linux-pm.orig/include/linux/cpuidle.h
> +++ linux-pm/include/linux/cpuidle.h
> @@ -54,7 +54,6 @@ struct cpuidle_state {
> unsigned int exit_latency; /* in US */
> int power_usage; /* in mW */
> unsigned int target_residency; /* in US */
> - bool disabled; /* disabled on all CPUs */
>
> int (*enter) (struct cpuidle_device *dev,
> struct cpuidle_driver *drv,
> @@ -77,6 +76,7 @@ struct cpuidle_state {
> #define CPUIDLE_FLAG_POLLING BIT(0) /* polling state */
> #define CPUIDLE_FLAG_COUPLED BIT(1) /* state applies to multiple cpus */
> #define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
> +#define CPUIDLE_FLAG_UNUSABLE BIT(3) /* avoid using this state */
>
> struct cpuidle_device_kobj;
> struct cpuidle_state_kobj;
> Index: linux-pm/arch/sh/kernel/cpu/shmobile/cpuidle.c
> ===================================================================
> --- linux-pm.orig/arch/sh/kernel/cpu/shmobile/cpuidle.c
> +++ linux-pm/arch/sh/kernel/cpu/shmobile/cpuidle.c
> @@ -67,7 +67,7 @@ static struct cpuidle_driver cpuidle_dri
> .enter = cpuidle_sleep_enter,
> .name = "C2",
> .desc = "SuperH Sleep Mode [SF]",
> - .disabled = true,
> + .flags = CPUIDLE_FLAG_UNUSABLE,
> },
> {
> .exit_latency = 2300,
> @@ -76,7 +76,7 @@ static struct cpuidle_driver cpuidle_dri
> .enter = cpuidle_sleep_enter,
> .name = "C3",
> .desc = "SuperH Mobile Standby Mode [SF]",
> - .disabled = true,
> + .flags = CPUIDLE_FLAG_UNUSABLE,
> },
> },
> .safe_state_index = 0,
> @@ -86,10 +86,10 @@ static struct cpuidle_driver cpuidle_dri
> int __init sh_mobile_setup_cpuidle(void)
> {
> if (sh_mobile_sleep_supported & SUSP_SH_SF)
> - cpuidle_driver.states[1].disabled = false;
> + cpuidle_driver.states[1].flags = CPUIDLE_FLAG_NONE;

That will overwrite other flags value, bit operation should be used here
to remove CPUIDLE_FLAG_UNUSABLE.

> if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
> - cpuidle_driver.states[2].disabled = false;
> + cpuidle_driver.states[2].flags = CPUIDLE_FLAG_NONE;
>
> return cpuidle_register(&cpuidle_driver, NULL);
> }
> Index: linux-pm/drivers/cpuidle/cpuidle.c
> ===================================================================
> --- linux-pm.orig/drivers/cpuidle/cpuidle.c
> +++ linux-pm/drivers/cpuidle/cpuidle.c
> @@ -570,7 +570,7 @@ static int __cpuidle_register_device(str
> return -EINVAL;
>
> for (i = 0; i < drv->state_count; i++)
> - if (drv->states[i].disabled)
> + if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE)
> dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER;
>
> per_cpu(cpuidle_devices, dev->cpu) = dev;
> Index: linux-pm/drivers/cpuidle/poll_state.c
> ===================================================================
> --- linux-pm.orig/drivers/cpuidle/poll_state.c
> +++ linux-pm/drivers/cpuidle/poll_state.c
> @@ -53,7 +53,6 @@ void cpuidle_poll_state_init(struct cpui
> state->target_residency_ns = 0;
> state->power_usage = -1;
> state->enter = poll_idle;
> - state->disabled = false;
> state->flags = CPUIDLE_FLAG_POLLING;
> }
> EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);
>
>
>


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